JP2020192240A - Absorbent article - Google Patents

Abstract

To provide an absorbent article that while holding a large quantity of highly absorbent polymer particles, is thin, has slight gel blocking and reduction in absorption speed, has excellent softness and touch, and inexpensive.SOLUTION: An absorbent article includes: a liquid permeable top sheet; a liquid impermeable back sheet; and an upper and lower two-layered absorbers disposed between the top sheet and the back sheet. The upper absorber includes two absorber pieces that are made to be bilaterally symmetric by taking the center in a width direction of the absorbent article as a boundary. The two absorber pieces are disposed so as to be at a predetermined interval in the width direction; and the whole of each absorber piece has small sections into which a carrier sheet is divided by performing heat-seal on the carrier sheet with a polygonal regular pattern.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inner pad type absorbent article.

Inner pads used in combination with tape-type disposable diapers are required to have a larger absorption amount for the purpose of reducing the number of replacements due to the labor shortage of care workers in recent years, and rewetting is required so that the wearer does not feel uncomfortable. Good things are required.

In order to meet such demands, the amount of super absorbent polymer particles used among fluff pulp and super absorbent polymer (hereinafter, also referred to as SAP) particles, which are widely used as absorbents for disposable disposable diapers, is used. There are ways to increase it. However, since there is an upper limit to the amount of highly absorbent polymer particles that can be supported inside a certain volume of fluff pulp between fibers, fluff pulp is used when the amount of highly absorbent polymer particles above a certain level is provided inside the absorber. Will increase the amount used. As a result, the thickness of the absorber is increased, and as a result, the thickness of the absorbent article is also increased.

In order to avoid this problem, a liquid-permeable non-woven fabric sheet or the like is used as a method of supporting a large amount of highly absorbent polymer particles inside the absorber while keeping the absorber thin. Various methods have been proposed in which highly absorbent polymer particles are supported on one surface of a non-woven fabric or between a plurality of non-woven fabrics by an adhesive or heat-sealing means and used as a part or all of the absorber.

For example, as in the technique described in Patent Document 1, many proposals have been made to devise the arrangement of highly absorbent polymer particles. However, in this thin absorber, when the highly absorbent polymer particles have a high density and are placed near the surface of the disposable diaper on the side in contact with the skin, gel block occurs and the absorption rate is lowered. There were drawbacks. Further, there is a problem that the amount of the highly absorbent polymer particles that can be supported on the non-woven fabric by the adhesive is limited, and that the sheet becomes hard due to the large amount of the adhesive, resulting in poor wearing feeling. In addition, since the adhesive is not hydrophilic, there is a problem that it causes a decrease in absorption performance.

Further, as a thin absorber, as described in Patent Document 2, a method has been proposed in which one non-woven fabric forms a three-dimensional small compartment, and high-absorbent polymer particles are packed and bonded to the other non-woven fabric sheet. It has been proposed that many highly absorbent polymer particles can be retained by this, and the absorption performance can be improved while being thin. However, in this method, since the thin absorber contains only the highly absorbent polymer particles in the compartment, the wearer feels the graininess of the particles before the highly absorbent polymer particles absorb the body fluid, and the middle of the absorbent article. After only partially absorbing the body fluid, when the caregiver pulls out the absorbent article for replacement, the particles may rub against the wearer's skin and cause pain, which is a drawback on the touch.

Japanese Unexamined Patent Publication No. 2004-329664 JP-A-2017-189644

Since the thin absorber composed of the conventional non-woven fabric and the highly absorbent polymer particles is substantially rectangular, there is a drawback that when the thin absorber is used as the absorber in this shape, the wearing feeling around the legs is poor. As a method for solving this, a method of cutting and removing a part of the undercarriage part of the rectangular absorber and deforming the underbody part into an hourglass shape is widely known. In the method, it is necessary to remove and dispose of the portion to be cut and removed, and since expensive high-absorbent polymer particles are present in this cut portion, there remains an economic problem that the manufacturing cost is large. Further, when a slit is provided in the thin absorber in order to prevent a decrease in the absorption rate, it must be cut, removed, and discarded in the same manner, and there is a problem that it is difficult to reduce the cost of manufacturing the absorber.

Therefore, the present invention has been made in view of such circumstances, and while supporting a large amount of highly absorbent polymer particles, it is thin, has little decrease in gel block and absorption rate, and has good softness and texture. It is an object of the present invention to provide an inexpensive absorbent article.

The inventor of the present invention has conducted diligent research in view of the above problems. As a result, in the absorbent article composed of the upper and lower two-layer absorbers, the composition of the upper layer absorber is acetate tow and the highly absorbent polymer particles, and the composition of the lower layer absorber is pulp and the highly absorbent polymer particles. We have found that the above problems can be solved by heat-sealing the whole with a regular pattern of polygons, and have completed the present invention. Specifically, the present invention provides the following.

(1) The first aspect of the present invention is an absorption having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an upper and lower two-layer absorber arranged between the top sheet and the back sheet. The upper layer absorber is composed of acetate tow, highly absorbent polymer particles and a carrier sheet of a thermoplastic non-woven fabric, and the lower layer absorber is composed of pulp and highly absorbent polymer particles, which is almost the same as the absorbent article. The upper layer absorber has the same shape and has two absorbent pieces symmetrical with respect to the center in the width direction of the absorbent article, and the two absorbent pieces are arranged at predetermined intervals in the width direction. Absorbency, and each absorber piece as a whole has subdivisions divided by heat fusion of the carrier sheet in a regular polygonal pattern. It is an article.

(2) The second aspect of the present invention is the absorbent article according to (1), wherein the upper layer absorber uses an adhesive for fixing the highly absorbent polymer particles to the acetate tow. It is characterized by the absence.

(3) The third aspect of the present invention is the absorbent article according to (1) or (2), in which the line width of the heat-sealed portion divided into the patterns is 3 mm or more and 10 mm or less. It is characterized by.

(4) A fourth aspect of the present invention is the absorbent article according to any one of (1) to (3), in which the lines of the heat-sealed portion divided into the patterns are partially opened. It is characterized by being done.

(5) A fifth aspect of the present invention is the absorbent article according to any one of (1) to (4), wherein the distance between the two absorber pieces in the width direction is 10 mm or more and 30 mm or less. It is characterized by being.

Therefore, according to the present invention, it is possible to provide an inexpensive absorbable article which is thin, has little decrease in gel block and absorption rate, has good softness and texture, and supports a large amount of highly absorbent polymer particles. ..

It is a top view of the absorbent article of this invention seen from the body side surface. It is sectional drawing of the straight line XX'in FIG. It is an enlarged view which shows the polygonal pattern in the heat fusion of the upper layer absorber of the absorbent article of this invention. It is a figure which shows the detail of the polygonal pattern of FIG. It is sectional drawing of the straight line YY'in FIG. It is a figure which shows the process of forming the upper layer absorber of the absorbent article of this invention. It is sectional drawing which shows the formation process of the upper layer absorber of the absorbent article of this invention.

Hereinafter, the absorbent article 1 according to the embodiment of the present invention will be described in detail, but these are listed for the purpose of exemplification and do not limit the present invention. The same elements are numbered the same throughout the description of the embodiment.

In the description of the present specification, the longitudinal direction is a direction extending in front of and behind the wearer when the absorbent article 1 is worn, and is a direction indicated by Y in the drawing. Further, the width direction is a direction laterally or orthogonal to the longitudinal direction, and is a direction indicated by X in the drawing. Further, in the present specification, the body-side surface refers to the surface that comes into contact with the wearer's skin when the absorbent article 1 is worn or the surface that comes into contact with the wearer's skin when the absorbent article 1 is worn. The side surface is the surface opposite to the body side surface, and is the surface that comes into contact with the wearer's clothing when the absorbent article 1 is worn or the side that comes into contact with the wearer's clothing when the absorbent article 1 is worn. Refers to the surface. Further, the absorbent article 1 according to the embodiment of the present invention may be an absorbent article 1 such as a pants-type disposable diaper or a tape-stopping disposable diaper.

<Absorbable article>
FIG. 1 is a plan view of the absorbent article 1 of the present invention as viewed from the body side surface, and FIG. 2 is a cross-sectional view of the straight line XX'in FIG. As shown in FIG. 1, the absorbent article 1 has an hourglass shape, and the longitudinal dimension L1 is preferably 350 mm or more and 800 mm or less, and the width direction dimension W1 of the front convex portion is 160 mm or more and 360 mm or less. The widthwise dimension W2 of the central concave portion is preferably 100 mm or more and 250 mm or less, and the widthwise dimension W3 of the rear convex portion is preferably 200 mm or more and 400 mm or less. By adjusting the dimensions of the absorbent article 1 within the above range, an absorbent article 1 suitable for pants-type disposable diapers, tape-stopping disposable diapers, and the like can be obtained.
Further, as shown in FIG. 2, the absorbent article 1 has a liquid-permeable top sheet 10 arranged on the body side surface and a liquid-impermeable top sheet 10 facing the top sheet 10 and arranged on the clothing side surface. It includes a back sheet 20, and two upper and lower layers of absorbers arranged between the top sheet 10 and the back sheet 20. As a result, the upper and lower two-layer absorbers, that is, the upper layer absorber 30 and the lower layer absorber 31, have a structure sandwiched between the top sheet 10 and the back sheet 20. The top sheet 10 and the back sheet 20 may be adhered to each other by an adhesive, heat fusion, or the like.

[Top sheet]
The top sheet 10 used in the absorbent article 1 according to the embodiment of the present invention allows the body fluid to quickly pass toward the upper layer absorber 30 and the lower layer absorber 31, and the upper layer absorber 30 and the lower layer absorber 31. Is placed so as to face the back sheet 20. Since the top sheet 10 is a sheet that comes into contact with the skin, it is preferably a hydrophilic non-woven fabric that has a soft feel and does not irritate the skin. Examples of the hydrophilic non-woven fabric include thermal-bonded non-woven fabrics such as air-through non-woven fabrics, spunlaced non-woven fabrics, spunbonded non-woven fabrics, and open polyethylene films using synthetic fibers such as polypropylene and polyethylene, recycled fibers such as rayon, and natural fibers such as cotton. An open film, a foamed film such as urethane foam, or the like can be used, and from the viewpoint of breathability and touch when worn, it is preferable to use a thermal bond non-woven fabric such as a hydrophilic air-through non-woven fabric or a spun bond non-woven fabric.

The basis weight of the top sheet 10 is preferably 18 g / m ² or more and 40 g / m ² or less from the viewpoint of workability and strength. In addition, lotions, antioxidants, anti-inflammatory components, pH adjusters, antibacterial agents, moisturizers and the like may be applied to the top sheet 10 in order to reduce irritation to the skin.

[Backsheet]
The back sheet 20 used in the absorbent article 1 according to the embodiment of the present invention is a sheet material having liquid impermeable property, and faces the top sheet 10 with the upper layer absorber 30 and the lower layer absorber 31 sandwiched therein. Be placed. As the back sheet 20, a sheet material using a thin plastic sheet such as a polyethylene sheet or a polyethylene laminated non-woven fabric can be used. In addition, it may have moisture permeability to prevent stuffiness.
The basis weight of the back sheet 20 is preferably 15 g / m ² or more and 40 g / m ² or less from the viewpoint of workability and strength.

[Absorber]
In the absorbent article 1 according to the embodiment of the present invention, the absorber used for the absorbent article 1 is an upper layer absorber 30 having two symmetrical absorber pieces with the center in the width direction as a boundary, and the absorbent article. It is composed of two types of absorbers, an hourglass-shaped lower layer absorber 31, which has almost the same shape as 1.
Each of the two absorber pieces of the upper layer absorber 30 preferably has a longitudinal dimension of 300 mm or more and 750 mm or less, and a widthwise dimension of the front and rear convex portions preferably 60 mm or more and 150 mm or less. The widthwise dimension of the recess in the central portion is preferably 30 mm or more and 100 mm or less. Further, the longitudinal dimension of the lower layer absorber 31 is preferably 300 mm or more and 750 mm or less, the width direction dimension of the front convex portion is preferably 110 mm or more and 310 mm or less, and the width direction of the concave portion in the central portion. The dimension is preferably 50 mm or more and 200 mm or less, and the widthwise dimension of the rear convex portion is preferably 150 mm or more and 350 mm or less.

The upper layer absorber 30 and the lower layer absorber 31 contain absorbent fibers as a base material and SAP particles, while the upper layer absorber 30 contains acetate tow as an absorbent fiber and the lower layer absorber 31 is an absorbent fiber. Contains pulp as. Acetate tow is a fiber bundle of diacetate fiber made from cellulose acetate having a degree of substitution of hydroxyl groups of about 2.5, and the acetate tow used in the present invention is the same as that used in a cigarette filter. it can. Further, in order to improve the softness and texture of the absorbent article 1, it is preferable that the upper layer absorber 30 does not use an adhesive for fixing SAP particles to the acetate tow.
As the pulp used for the lower layer absorber 31, fluff pulp is preferable. Examples of the fluff pulp include wood pulp (for example, softwood bleached kraft pulp (N-BKP) such as Southern pine and Douglas fir), non-wood pulp and the like defibrated into cotton. The absorbent fibers of the upper layer absorber 30 preferably have a basis weight of 180 g / m ² or more and 500 g / m ² or less so as not to impair the absorption performance and touch of each of the upper layer absorber 30 and the lower layer absorber 31. The absorbent fiber of the absorber 31 preferably has a basis weight of 180 g / m ² or more and 375 g / m ² or less.

The SAP particles used for the upper layer absorber 30 and the lower layer absorber 31 are not particularly limited as long as they can absorb body fluids and prevent backflow, and are sodium polyacrylate-based, polyaspartate-based, (starch). A material formed from a material such as a (acrylic acid) graft copolymer, a (acrylic acid-vinyl alcohol) copolymer, a (isobutylene-maleic anhydride) copolymer and a saponified product thereof can be used. Among these, sodium polyacrylate-based copolymers are preferable from the viewpoint of the amount of absorption per mass. The SAP amount of the upper layer absorber 30 is preferably 100 g / m ² or more and 400 g / m ² or less, preferably 150 mass, so as not to impair the absorption performance and touch of each of the upper layer absorber 30 and the lower layer absorber 31. The content is preferably% or more and 300% by mass or less. The SAP amount of the lower layer absorber 31 is preferably 70 g / m ² or more and 125 g / m ² or less, and preferably 80% by mass or more and 100% by mass or less.

In the upper layer absorber 30 and the lower layer absorber 31, the form of the absorbent fiber and the SAP particle is preferably the form of a mat formed by mixing the SAP particle in the absorbent fiber. Further, the upper layer absorber 30 is wrapped in the carrier sheet 50 for the purpose of preventing leakage of SAP particles and stabilizing the shape. As for the lower layer absorber 31, a carrier sheet 51 is used for the purpose of transporting in the manufacturing process and preventing leakage of SAP particles, and is preferably arranged between the lower layer absorber 31 and the back sheet 20 as shown in FIG.
The base material of the carrier sheet 50 is not particularly limited as long as it is a thermoplastic non-woven fabric, but the basis weight is preferably 25 g / m ² or more. If the basis weight of the carrier sheet 50 is less than 25 g / m ² , the amount of resin is small and sufficient strength at the time of fusion cannot be obtained. The base material of the carrier sheet 51 is not particularly limited as long as it has liquid permeability, and examples thereof include liquid-permeable non-woven fabrics such as tissue, absorbent paper, and air-laid non-woven fabric. In the carrier sheet 50 and the carrier sheet 51, the respective base materials may be the same or different, and the wrapping method when wrapping the upper layer absorber 30 with the carrier sheet 50 is not particularly limited. Absent.

The basis weight of the upper layer absorber 30 is preferably 180 g / m ² or more and 500 g / m ² or less, and the basis weight of the lower layer absorber 31 is 180 g / m ² or more and 375 g / m ² or less. preferable. By setting the basis weights of the upper layer absorber 30 and the lower layer absorber 31 within the above ranges, the absorbent article 1 has excellent absorbency and can effectively prevent leakage of body fluid.
Further, the two absorber pieces of the upper layer absorber 30 are arranged at predetermined intervals L in the width direction. At this time, the interval L is preferably 10 mm or more and 30 mm or less, and more preferably 15 mm or more and 25 mm or less. By arranging the two absorber pieces at intervals L, the absorbent article 1 having a slit portion capable of directly feeding the body fluid to the lower layer absorber 31 can be obtained.

The entire absorber piece of the upper layer absorber 30 has subdivisions divided by heat-sealing the carrier sheet 50 in a regular polygonal pattern. FIG. 3 is an enlarged view of a regular polygonal pattern of the heat-sealed portion 60 applied to the entire upper layer absorber 30. Further, FIG. 7 is a cross-sectional view showing a step of forming the upper layer absorber 30.
In an absorbent article, SAP particles can be supported without an adhesive by three-dimensionally opening the acetate tow, which is a long fiber. However, although the detailed cause is unknown, the movement and dropout of SAP particles are small immediately after processing, but the SAP particles become easier to move over time. This tendency is seen as the amount of SAP particles added is increased. As shown in FIGS. 7 (a) and 7 (b), in the absorbent article 1 of the present invention, first, acetate tow and SAP particles are wrapped with a carrier sheet 50 to form an absorber core 301, which is then shown in FIG. The heat-sealing portion 60 shown in the above is divided into compartments separated by a regular polygonal pattern. Therefore, the movement of SAP particles occurs only within the compartment of the pattern shown in FIG.

FIG. 5 shows a cross-sectional view of the straight line YY'of FIG. As shown in FIG. 5A, the acetate tow 302 and the SAP particles 303 are uniformly dispersed immediately after the upper layer absorber 30 is formed, but the distribution of the SAP particles 303 as shown in FIG. 5B over time. Is biased downward. However, the movement in the horizontal direction is restricted by dividing the entire upper layer absorber 30 into a regular polygonal pattern of the heat-sealing portion 60. Further, since the SAP particles 303 are biased downward, the upper region where the distribution of the SAP particles 303 is small becomes a porous fiber layer, which helps the upper layer absorber 30 to take in the body fluid and spread the body fluid in the horizontal direction. Further, as shown in FIGS. 2 and 7 (c), since the heat-sealing portion 60 is applied to the entire upper layer absorber 30, the body fluid under the top sheet 10 is diffused in the horizontal direction. It serves as a fluid passage and helps improve the absorption rate.

In each section of the pattern shown in FIG. 3, the acetate tow, which is a bulky fiber, is adhered to the carrier sheet 50 by heat fusion, so that the cross sections shown in FIGS. 5 (a) and 7 (b) can be seen. , It has cushioning unevenness. Originally, the upper layer absorber 30 has a dry feeling due to the high content of SAP particles, but the unevenness reduces the contact area of the absorbent article 1 with the body of the wearer and allows the fluid to pass through after absorbing the body fluid. The road becomes a steam passage to reduce stuffiness. Therefore, the dry feeling of the absorbent article 1 is further enhanced, and the texture can be improved.
FIG. 4 is a diagram showing details of the polygonal pattern of FIG. The dimensions of each section of the polygonal pattern are such that the short side P1 is preferably 0 mm or more and 50 mm or less, the long side P2 is preferably 25 mm or more and 60 mm or less, and the height P3 is 20 mm or more and 60 mm or less. It is preferable to have.

Further, in the polygonal pattern, the line width P4 of the heat-sealed portion 60 is preferably 3 mm or more and 10 mm or less. When P4 is less than 3 mm, the heat fusion is locally weakened in the portion of the SAP particles supported on the acetate tow, so that the overall fusion strength of the upper layer absorber 30 is relatively weak. The heat fusion is easy to peel off. Although it depends on the shape and size of the fusion pattern and the shape and size of the compartment, when P4 exceeds 10 mm, the area where the acetate toe swells and becomes like a cushion becomes too small, and the absorbent article 1 Inferior in softness and texture.

Further, as shown in FIG. 3, the heat-sealed portion 60 of the upper layer absorber 30 is partially perforated, that is, the perforated portions 70 are regularly provided on the line of the heat-sealed portion 60. preferable. In the absorbent article 1 of the present invention, by regularly providing the opening portions 70 on the line of the heat-sealing portion 60, the lower layer absorber 31 is provided with the distance L between the two absorber pieces of the upper layer absorber 30. It can help the passage of body fluids, resulting in a good absorption rate. At this time, the width direction dimension of the hole 70 is preferably 1 mm or more and 2 mm or less, the longitudinal dimension is preferably 2 mm or more and 6 mm or less, and the distance between the hole 70s is 4 mm or more and 30 mm or less. Is preferable. By setting the size and spacing of the perforations 70 within the above range, the fusion strength of the heat-sealing portion 60 of the upper layer absorber 30 is maintained, and the passage of the body fluid through the lower layer absorber 31 is assisted. As a result, the absorption rate can be made good.
As shown in FIG. 3, the case where the opening portion 70 is provided only on the line in the longitudinal direction of the heat fusion portion 60 is relatively larger than the case where the opening portion 70 is provided on the line in the width direction or the diagonal direction. It is preferable because the position where the opening portion 70 is provided can be easily determined, but the opening portion 70 may be provided on a line in the width direction or the diagonal direction.

[Three-dimensional gather]
On the body side surface of the absorbent article 1 according to the embodiment of the present invention, in order to prevent lateral leakage of the body fluid excreted by the user, an elastic member for three-dimensional gathering and a three-dimensional object are formed along the longitudinal direction of the absorbent article 1. A pair of three-dimensional gathers 40 having gather sheets may be provided. It is preferable that the three-dimensional gather 40 is fixed to the back sheet 20 at the widthwise end (fixed end) of the absorbent article 1, and the free end side is folded in half at the end. The elastic member for three-dimensional gathers is preferably sandwiched between two-folded three-dimensional gather sheets on the free end side. As a result, the three-dimensional gather 40 has an upright property and can be deformed according to the wearer's body shape.

As the elastic member for three-dimensional gather, for example, polyurethane thread, band-shaped polyurethane film, synthetic rubber, thread-shaped or band-shaped natural rubber, or the like can be used, and thread-shaped, string-shaped, or flat-shaped members can be appropriately used. .. Further, as the three-dimensional gather sheet, a water-repellent or impermeable non-woven fabric formed of hydrophobic fibers, for example, a spunbonded non-woven fabric, a melt-blown non-woven fabric, a composite non-woven fabric in which spunbond / meltblown / spunbond is laminated, or the like is used. Will be done. The basis weight of the three-dimensional gather sheet is preferably 10 g / m ² or more and 25 g / m ² or less.

<Manufacturing method of absorbent articles>
The method for producing the absorbent article 1 includes the following steps.
First, as shown in FIG. 7A, the acetate tow is opened by air, and SAP particles are supported to form the absorber core 301, and then the carrier sheet 50, which is a water-permeable and thermoplastic non-woven fabric, is formed. By wrapping the entire absorber core 301 with, one continuous absorber 32 is formed.
Then, as shown in FIGS. 6A and 7B, the entire single continuous absorber 32 is fused in a regular polygonal pattern.

Next, as shown in FIGS. 6 (b) and 7 (c), one continuous absorber 32 is cut so as to meander from the center in the width direction to the left and right alternately at equal intervals in the longitudinal direction. The separated absorbers form a pair of continuous absorbers 33 facing each other in the width direction.
Then, as shown in FIG. 6B, in the pair of separated continuous absorbers 33, the unevenly shaped cut portions are formed so as to face inward in the width direction of each other, but then a pair of continuous absorbers are absorbed. The direction of the cut portion of the body 33 is adjusted so as to face outward in the width direction as shown in FIG. 6 (c). At this time, it is preferable that the direction adjustment includes a step of reversing the pair of separated continuous absorbers 33 in the direction R indicated by the arrow in FIG. 6B, that is, outward in the width direction.

Next, the positions of the concave-convex shapes of the pair of continuous absorbers 33 whose directions have been adjusted are phase-adjusted in the longitudinal direction, and as shown in FIG. 6D, the convexes and the concaves are aligned in the same phase in the longitudinal direction. Match the phases as follows.
Then, the pair of phase-adjusted continuous absorbers 33 are separated by straight lines provided at regular intervals in the direction substantially perpendicular to the longitudinal direction at each outward convex portion, as shown in FIG. 6 (e). An upper layer absorber 30 having two symmetrical absorber pieces is obtained with the center in the width direction as a boundary.

Finally, the pair of left and right upper layer absorbers 30 obtained in the above-mentioned final molding step are laminated on the lower layer absorber 31 laminated on the back sheet 20, and the three-dimensional gather 40 and the top sheet 10 are laminated. Thereby, the absorbent article 1 is formed.
Further, at this time, as described above, by arranging the two absorber pieces of the upper layer absorber 30 at intervals L, the absorption having a slit portion capable of directly feeding the body fluid to the lower layer absorber 31. Sex article 1 is obtained.

Although the present invention has been described above using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope of the invention described in the above embodiments. It will be apparent to those skilled in the art that improvements can be made. Further, it is clear from the description of the claims that the form in which such a modification or improvement is added may be included in the technical scope of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to the examples shown below.

<Example 1>
[Creation of upper absorber]
The upper layer absorber was prepared by the following method. First, an acetate tow carrying SAP particles was prepared. The preparation method was the method disclosed in JP-A-2018-59239. Specifically, an acetate tow having a width of 57 g / m ² and a width of 110 mm before opening was spread in the width direction by two widening devices, and then two roll pairs were passed through. At this time, by making the peripheral speed of the roll pair on the downstream side faster than that on the upstream side, the acetate tow in the crimped state is stretched and pre-opened. At the same time as adding SAP particles to this, the fibers are further opened by high-pressure air (jet) flowing in the acetate toe transport direction, and a continuum (absorption) of the acetate toe molded product carrying rod-shaped SAP particles having a width of about 120 mm and a thickness of about 30 mm. Body core) was prepared. The amount of SAP particles added was adjusted to be 10 g with respect to 2.5 g of acetate tow. This is placed approximately in the center of a carrier sheet which is a non-woven fabric made of a thermoplastic fiber having a width of 270 mm, and the carrier sheet is pressed while being folded from both ends. As shown in FIG. 7A, the entire absorber core is formed by the carrier sheet. Wrapped. As shown in FIG. 6A, this was divided into small sections by heat fusion in a regular pattern of polygons. As the non-woven fabric, an air-through non-woven fabric having a basis weight of 30 g / m ² was used.

[Fusion, division, alignment of upper absorber]
As a regular pattern of polygons, a quadrangle having a short side P1 of 7.5 mm, a long side P2 of 35 mm, and a height P3 of 20 mm was combined as shown in FIGS. 3 and 4. The line width P4 of the heat-sealed portion was set to 6 mm.
A continuous absorber was divided along the heat-sealing line divided into this section to form a pair of continuous absorbers. At this time, it was divided so as to meander from the center in the width direction to the left and right alternately at equal intervals in the longitudinal direction. In this embodiment, the combination of one set of short side and long side is changed to four sets in the longitudinal direction, and the length including the short side at both ends thereof is changed to the left and right via the inclined portion every 185 mm. After the left and right sides of the pair of continuous absorbers were exchanged and the position of one side was adjusted in the longitudinal direction, the two absorbers were arranged with a width of 15 mm apart. A pair of continuous absorbers were cut so that the longitudinal direction was 50 mm on the front side, 185 mm on the center portion, and 135 mm on the rear side and had a total length of 425 mm, and after molding the upper layer absorber, it was placed on the lower layer absorber.

(Creation of lower absorber)
From 26 g of defibrated fluff pulp and 10 g of SAP particles, an hourglass-shaped lower layer absorber having a length of 540 mm, a maximum width of 220 mm on the front side, a crotch portion of 180 mm, and a maximum width of 260 mm on the rear side was prepared by a usual method, and the basis weight was increased. It was carried on a tissue having a width of 16 g / m ² and a width of 180 mm, and proceeded to the step of mounting the above-mentioned upper layer absorber.

(Creation of finished absorbent article)
As a back sheet, a polyethylene film (18 g / m ² ) with a width of 320 mm is placed, and absorbers for each of the lower and upper layers are installed, and a top sheet with three-dimensional gathers on both sides in advance is placed on it. Hourglass-shaped absorbent articles having a longitudinal dimension of 630 mm and a width dimension of 280 mm in the front side, 238 mm in the center, 320 mm in the rear side, and 4 mm in thickness were obtained. A hot melt adhesive was used to bond each layer.

(Confirmation of absorption performance)
Use the obtained absorbent article as a tape-stopping type outer absorbent article (tape-stopping type ML size with acti pad, thickness 6 mm) and wear it on a supine paper diaper / sanitary product evaluation dummy doll. It was. 150 ml of saline colored with blue food coloring was poured 5 times at 10 minute intervals. Since the dummy doll is made of transparent resin, the flow of water on the surface side of the water-absorbent article can be observed.

A similar test was also performed on commercially available absorbent articles (Acty Wide Pad 1000, manufactured by Nippon Paper Crecia Co., Ltd.) having the same content of SAP particles. In the absorbent article of Example 1, the physiological saline solution hardly stayed on the top sheet in the second water injection, and water was absorbed in a wide range from the urinary part to the buttock side due to the degree of coloring. It is probable that it entered the inside from the top sheet and diffused through the groove formed by heat fusion. In addition, since the upper layer absorber and its surroundings were mainly colored, it is considered that water was absorbed mainly by the upper layer absorber. From the third time onward, the liquid was slightly visible on the surface, but the liquid disappeared from the surface in about 5 seconds after the pumping was completed. When 10 minutes had passed after the fifth water injection, the diaper was removed and the surface of the product of the present invention was touched to confirm a dry feeling. As a result, no wet feeling was felt, and unevenness was felt under the top sheet. Moreover, the liquid did not return even if it was lightly pressed by hand.
On the other hand, in the commercial product, a liquid pool was formed in the crotch from the second time, and the liquid was slowly absorbed. In addition, when the diaper was removed after the fifth water injection and the surface of the commercially available product was touched with a hand to check the dry feeling, the hand felt a little wet. In addition, when pressed by hand, there was a slight return of liquid in the part near the urination port.

After performing the above test, the absorbent article of Example 1 was cut in several places with scissors in the width direction and the water absorption state in the vertical direction was confirmed. As a result, it was colored from 10 cm to the rear side of the urination port. However, most of the crotch area was colored only in the upper layer absorber, and the lower layer absorber was hardly colored. This is because the upper absorbers are placed at intervals, but in the crotch, the absorbers are bent and pulled together so that they fit in the legs, and this gap is blocked, blocking the flow path of the liquid to the lower absorbers. Because it is. Furthermore, the vertical wrinkles generated by the upper layer absorbers and the grooves formed by heat fusion of the upper layer absorbers serve as a flow path for the liquid, and there is less SAP on the body side inside the upper layer absorbers, which is porous. It is considered that this is because the flow of the liquid in the plane direction is stronger and the movement of the liquid from the central gap of the upper layer absorber to the lower layer is unlikely to occur. Behind the crotch, the lower absorber was also sufficiently absorbed.

<Example 2>
After heat-sealing to divide into compartments, holes with a length of 1.5 mm in the width direction and a size of 5 mm in the length direction are formed at intervals of 15 mm in the fusion line in the longitudinal direction. An absorbent article was prepared in the same process as in Example 1 except that it was provided.
In the same manner as in Example 1, the paper diaper in the supine position and the dummy doll for evaluation of sanitary products were worn and water was injected 5 times. The state of water absorption from the top sheet side and the dry feeling after absorbing water 5 times were the same as in Example 1, but since the amount of water absorbed by the lower layer absorber in the crotch was increased, it was absorbed more than in Example 1. It turned out that I was able to use my body effectively.
Based on the above, according to the present invention, it is possible to provide an inexpensive absorbent article that is thin, has little decrease in gel block and absorption rate, has good softness and texture, and supports a large amount of SAP particles.

1 Absorbent article 10 Top sheet 20 Back sheet 30, 31, 32, 33 Absorber 40 Three-dimensional gather 50, 51 Carrier sheet 60 Heat fusion part 70 Perforation part 301 Absorber core 302 Acetate toe 303 SAP particles

Claims (5)

An absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an upper and lower two-layer absorber arranged between the top sheet and the back sheet.
The upper absorber consists of acetate tow, highly absorbent polymer particles and a carrier sheet of thermoplastic non-woven fabric.
The lower layer absorber is composed of pulp and highly absorbent polymer particles, and has almost the same shape as the absorbent article.
The upper layer absorber has two absorber pieces symmetrical with respect to the center in the width direction of the absorbent article, and the two absorber pieces are arranged at a predetermined interval in the width direction. An absorbent article, wherein each absorber piece as a whole has subdivisions divided by heat fusion of carrier sheets in a regular polygonal pattern. The absorbent article according to claim 1, wherein the upper layer absorber does not use an adhesive for fixing the highly absorbent polymer particles to the acetate tow. The absorbent article according to claim 1 or 2, wherein the line width of the heat-sealed portion divided into the patterns is 3 mm or more and 10 mm or less. The absorbent article according to any one of claims 1 to 3, wherein the line of the heat-sealed portion divided into the pattern is partially perforated. The absorbent article according to any one of claims 1 to 4, wherein the distance between the two absorber pieces in the width direction is 10 mm or more and 30 mm or less.

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